What that riddle does to words, There Is No Game does to the scenery and infrastructure of a computer game. What looks like part of the background or an element of the user interface might be an item you can interact with and repurpose in an ingenious way that shouldn't work and yet somehow does, like Mark Watney in The Martian turning space suits into water tanks for his potato farm and a motorised camera into a two-way communication device.
This is a game about thinking outside the box, often literally. It doesn't just break the fourth wall, it gleefully demolishes it and gives you the pieces to play with.
There's a chapter inspired by point-and-click adventures (think Monkey Island), one based on role-playing games (think Zelda), and one viciously parodying the new breed of free-to-play, pay-to-win Skinner-box games. But you don't play as the detective protagonist of the point-and-click game or the adventurer hero of the RPG; you get to look behind the scenes (complete with half-painted wooden scenery) and advance your own goals, while the actual protagonist bumbles around pursuing theirs, unknowingly helping or hindering you.
This is a game that celebrates ingenuity, persistence, and the sheer bloody-mindedness of players who refuse to accept the narrator's repeated insistence that there's nothing to see here and you should quit the game and find something else to do. It rewards the perversity of doing the opposite of what you're told and believing the opposite of what you're told. And those rewards are great: there is a unique gem of a game waiting to be discovered by those who don't give up easily.
(By which I mean, of course, that there is no game.)